Problem: A permutation p is an ordered group of numbers p1, p2, ..., pn, consisting of n distinct positive integers, each is no more than n. We'll define number n as the length of permutation p1, p2, ..., pn.

Simon has a positive integer n and a non-negative integer k, such that 2k ≤ n. Help him find permutation a of length 2n, such that it meets this equation: <image>.

Input

The first line contains two integers n and k (1 ≤ n ≤ 50000, 0 ≤ 2k ≤ n).

Output

Print 2n integers a1, a2, ..., a2n — the required permutation a. It is guaranteed that the solution exists. If there are multiple solutions, you can print any of them.

Examples

Input

1 0


Output

1 2

Input

2 1


Output

3 2 1 4


Input

4 0


Output

2 7 4 6 1 3 5 8

Note

Record |x| represents the absolute value of number x. 

In the first sample |1 - 2| - |1 - 2| = 0.

In the second sample |3 - 2| + |1 - 4| - |3 - 2 + 1 - 4| = 1 + 3 - 2 = 2.

In the third sample |2 - 7| + |4 - 6| + |1 - 3| + |5 - 8| - |2 - 7 + 4 - 6 + 1 - 3 + 5 - 8| = 12 - 12 = 0.

Solution (in JAVA):

Solution:
//package clipse;


import java.util.*;
import java.util.function.Function;
import java.util.stream.Collectors;



import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Random;
import java.util.StringTokenizer;
import java.io.*;
import java.math.*;


public class C
{
	
	static StringBuilder sb;
	
	//static long dp[][];
	static int cnt=0;
	static long pre[];
	static long A[];
	
	
	
	
	
	static void solve()
	{
	int n=i();
	int k=i();
	
	
	n=2*n;
	
	int A[]=new int[n+1];
	for(int i=1;i<=n;i++)
		A[i]=i;
	
	int diff=2*k;
	int rem=n-2*k;
	
	for(int j=n;j>=0;j=j-2)
	{
		if(rem>0)
		{
			
			A[j]=j-1;
			A[j-1]=j;
			rem=rem-2;
		}
		else
			break;
	}
	for(int a:A)
		if(a!=0)
		System.out.print(a+" ");
	System.out.println();
	
		
		
	
	}
		
		
		
		
		
	
	

	 public static void main(String[] args)
	    {
		 
		 int p = 1000000007;
		 inverse obj=new inverse(100001);
		 obj.InverseofNumber(p);
		 obj.InverseofFactorial(p);
		 obj.factorial(p);
		 
		 int testcase=1;
		 		
	         sb=new StringBuilder();
	        int tmp=testcase;
	         while(testcase-->0)
	         {
	        	 
	        	 solve();
	         }
	         
	         System.out.println(sb);
	         
	    }
	 
	 
	 //*********************************Disjoint set union*************************//
	 static class dsu
	 {
		 int parent[];
		 int size[];
		 dsu(int n)
		 {
			 parent=new int[n];
			 size=new int[n];
			 Arrays.fill(size,-1);
			 for(int i=0;i<n;i++)
				 parent[i]=-1;
		 }
		 int find(int a)
		 {
			 if(parent[a]<0)
				 return a;
			 else
			 {
				 int x=find(parent[a]);
				 parent[a]=x;
				 return x;
			 }
		 }
		 void merge(int a,int b)
		 {
			 a=find(a);
			 b=find(b);
			 if(a==b)
				 return;
			 parent[b]=a;
			 size[a]+=size[b];
		 }
	 }
	 
	 
	 
//*******************************************PRIME FACTORIZE *****************************************************************************************************//
	 static TreeMap<Long,Long> prime(long n)
	 {
		 TreeMap<Long,Long>h=new TreeMap<>();
		 long num=n;
		 
		 for(int i=2;i<=Math.sqrt(num);i++)
		 {
			 if(n%i==0)
			 {
				 int nt=0;
				 while(n%i==0) {
					 n=n/i;
					 nt++;
				 }
				 h.put((long)i, (long)nt);
			 }
		 }
		 if(n!=1)
			 h.put((long)n, (long)1);
		 return h;
		 
	 }
	 
///////////////////////****************************************-----------------------------.........................>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>***********************************************	
	 
	static long [] xsort(long A[])
	{
		ArrayList<Long>l=new ArrayList<>();
		for(long a:A)
			l.add(a);
		Collections.sort(l);
		for(int i=0;i<l.size();i++)
			A[i]=l.get(i);
		
			return A;
		
		
	}
	 
	
//*************CLASS PAIR ***********************************************************************************************************************************************
	static class pair implements Comparable<pair>
    {
        long x;
        int y;

        pair(long x, int y) {
            this.x = x;
            this.y = y;
        }
        public int compareTo(pair o)
        {
        	return (int)(x-o.x);
        	
        }
		
       
    }
//*************CLASS PAIR *****************************************************************************************************************************************************
	
	
	

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1)
                throw new InputMismatchException();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public int Int() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public String String() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return String();
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);
        }
    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void print(Object... objects) {
            for (int i = 0; i < objects.length; i++) {
                if (i != 0)
                    writer.print(' ');
                writer.print(objects[i]);
            }
        }

        public void printLine(Object... objects) {
            print(objects);
            writer.println();
        }

        public void close() {
            writer.close();
        }

        public void flush() {
            writer.flush();
        }
    }

    static InputReader in = new InputReader(System.in);
    static OutputWriter out = new OutputWriter(System.out);
    static int modulus = (int) 1e7;

    public static int[] sort(int[] a) {
        int n = a.length;
        ArrayList<Integer> l = new ArrayList<>();
        for (int i : a)
            l.add(i);
        Collections.sort(l);
        for (int i = 0; i < l.size(); i++)
            a[i] = l.get(i);
        return a;
    }

    public static long pow(long x, long y) {
        long res = 1;
        while (y > 0) {
            if (y % 2 != 0) {
                res = (res * x) % modulus;
                y--;

            }
            x = (x * x) % modulus;
            y = y / 2;
        }
        return res;
    }
//GCD___+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    public static long gcd(long x, long y) {
        if (x == 0)
            return y;
        else
            return gcd(y % x, x);
    }
    //****************LOWEST COMMON MULTIPLE   *************************************************************************************************************************************

    public static long lcm(long x, long y) {
        return (x * (y / gcd(x, y)));
    }
//INPUT PATTERN******************************************************************************************************************************************************************
    public static int i() {
        return in.Int();
    }

    public static long l() {
        String s = in.String();
        return Long.parseLong(s);
    }

    public static String s() {
        return in.String();
    }

    public static int[] readArray(int n) {
        int A[] = new int[n];
        for (int i = 0; i < n; i++) {
            A[i] = i();
        }
        return A;
    }

    public static long[] readArray(long n) {
        long A[] = new long[(int) n];
        for (int i = 0; i < n; i++) {
            A[i] = l();
        }
        return A;
    }

//////////////////////////************************************INVERSE MODULO******************************************************************
static class inverse 
{
	static int N;
	static long[] factorialNumInverse;
	static long[] naturalNumInverse;
	static long[] fact;
	inverse(int n)
	{
		this.N=n;
		
		 factorialNumInverse = new long[N + 1];
		 
	    // Array to precompute inverse of 1! to N!
	     naturalNumInverse = new long[N + 1];
	 
	    // Array to store factorial of first N numbers
	     fact = new long[N + 1];
	 
	}
	

// Function to precompute inverse of numbers
static void InverseofNumber(int p)
{
naturalNumInverse[0] = naturalNumInverse[1] = 1;

for(int i = 2; i <= N; i++)
    naturalNumInverse[i] = naturalNumInverse[p % i] *
            (long)(p - p / i) % p;
}

// Function to precompute inverse of factorials
static void InverseofFactorial(int p)
{
factorialNumInverse[0] = factorialNumInverse[1] = 1;

// Precompute inverse of natural numbers
for(int i = 2; i <= N; i++)
    factorialNumInverse[i] = (naturalNumInverse[i] *
            factorialNumInverse[i - 1]) % p;
}

// Function to calculate factorial of 1 to N
static void factorial(int p)
{
fact[0] = 1;

// Precompute factorials
for(int i = 1; i <= N; i++)
{
    fact[i] = (fact[i - 1] * (long)i) % p;
}
}

// Function to return nCr % p in O(1) time
static long comb(int N, int R, int p)
{

// n C r = n!*inverse(r!)*inverse((n-r)!)
long ans = ((fact[N] * factorialNumInverse[R]) %
        p * factorialNumInverse[N - R]) % p;

return ans;
}
}
//////////////////////////************************************INVERSE MODULO******************************************************************
}